Venting device and method for anesthetic administration

ABSTRACT

A valve assembly in a circle absorber system includes a removable plug to permit limited escape of gases from the absorber system, and a manually adjustable body accommodating escape of additional volumes of gas as determined by adjustable registry of vent openings therein. A valve assembly cover is provided with a fitting connectible to a vacuum system to facilitate disposition of vented gases outside of the operating room environment.

1451 Aug. 14, 1973 United States Patent Dryden 77 MAABxWW 855663 NMQB"77 NUH n ma s u e mm mmn a MNCUO ML HAFL 8385lll 4556777 9999999HHHHHHH 395346 5779500 6278 9 1 1 1 13 1 4.245252 3358778 2223333 n l aw 0 .w a F 1. m wN m 0 m .m mu m M T m Wm M n mm E V k E zl m on 6 D1 Gmm a E m .m. EN m s VA 1 A 4 5 3 5 7 7 [22] Filed: Oct. 9, 1970 Primary.Examiner-Samuel Scott [21] Appl' No" 79,597 Att0rney-Woodard, Weikart,Emhardt and Naughton [52] U.S. 137/608, 251/310 511 Im. F17d 1/00 [571ABSTRACT of Search...................... A valve assembly in a circleabsorber system includes 251/310 a removable plug to permit limitedescape of gases from the absorber system, and a.manually adjustable [56]References Cited body accommodating escape of additional volumes ofUNITED STATES PATENTS gas as determined by adjustable registry of ventopen- 3,542,336 11/1970 01m 251/310 x 5 therein- A valve assembly coveris Provided with 3 1924 P r 251 3 1 x a fitting connectible toa vacuumsystem to facilitate 2 4/1958 Myers....... 251/310 X disposition ofvented gases outside of the operating 3 11/1963 Bozoyan "251/311 X roomenvironment.

8/1961 Huska....... 37/625.47'X 1 3/1914 Graham 137/610 X 7 Claims, ,5Drawing Figures 5 1 ay 4 x Patented Aug. 14, 1973 2 Sheets-Sheet l 5&3.

I mvemon 5445 E. .Dermw' ATTORNEYS Patented Aug. 14, 1973 3,752,186

2 Sheets-Sheet 2 INVENTOR 6.445 E. .DkYDE/V .AIP'IORNEYS VENTING DEVICEAND METHOD FOR ANESTHETIC ADMINISTRATION BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates generally toadministration of anesthetics, and more particularly to means forcontrolling release of gases from a circle absorber system duringanesthesia.

2. Description of the Prior Art Known prior art typically employs a gasmachine of conventional construction equipped to deliver gaseousinhalant mixtures of oxygen and/or air mixed with suitable anestheticgases. Suitable manually controlled valving is provided on such machinesso that the volume of gases consumed by the patient and extracted in theabsorber are replaced by delivery of gas to maintain the average volumeof the system substantually at equilibrium. The depth of anesthesia iscontrolled by regulating the concentration of the anesthetic gas in themixture delivered to the breathing circuit. The machines may be arrangedto respond to pressure for increasing or decreasing the volume of gasdelivered to the circuit. It is also possible to provide a pressuregauge or manometer for observation by the anesthetist to enable him toobserve and maintain pressure by the desired adjustments. Pressurerelief valves are also employed to avoid excessive pressures in suchsystems.

The technique of anesthetists varies somewhat. Some DESCRIPTION OF THEPREFERRED EMBODIMENT Referring now to the drawings in detail, aconventional anesthetic gas machine 11 is provided with a bracket 12 onwhich is mounted a unitary disposable cannister assembly 13 which may beof a type shown and described in my application Ser. No. 684,005, nowUS. Pat. No. 3,566,867, Mar. 2, l97l, filed Nov. 17, I967. In brief,such an assembly includes an upper chamber 14, a lower chamber 16, andan intermediate chamber between the lines 17 and 18, with the latterchamber 19 containing soda-lime, or other suitable absorbent materialfor carbon dioxide. A one-way valve in a fitting 21 permits flow of thebreathing mixture from the chamber at 14 through the hose 22 to the mask23. A one-way valve in the fitting 24 permits flow of gas through thehose 26 into the lower chamber 16. A re-breathing bag 27 is mounted tothe lower chamber, and a fitting 28 is provided to receive theanesthetic gas mixture through a hose 29 from a manually controllablevalve 31 on the gas machine 11.

A fitting 32 on the upper chamber is connected I through a hose 33 to apressure gauge 34 and pressure prefer to add approximately 3 to 4 litresof mixture per minute, while others may use up to 8 litres per minute.High rates of supply to the circuit by the gas machine usually exceedthe volume consumed by the patient and extracted in the absorber, sothere must be a re'gu lar and constant venting of gases. While a certainamount of this is tolerable, there is some disadvantage to venting anyamount of anesthetic mixture or the breathing mixture into the operatingroom atmosphere. Certainly the venting of large amounts is quiteobjectionable because of the obvious anesthetic effect it may have onoperating personnel.

SUMMARY OF THE INVENTION Described briefly, in a typical embodiment ofthe present invention, a disposable valve i s provided with a featureaccommodating low venting rates while permitting assistance to thebreathing of the patient by the usual techniques. It includes a manuallyadjustable feature to accommodate venting at high rates, and includesmeans for collecting the vented gas to avoid dissipation thereof in anoperating room.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of acircle absorber system incorporating the present invention.

FIG. 2 is an enlarged longitudinal section through a typical embodimentof a valve constructed according to the present invention.

FIG. 3 is a section taken at line 3-3 in- FIG. 2 and viewed in thedirection of the arrows, showing the valve adjusted for a high ventingrate.

FIG. 4 is a section like FIG. 3, but showing a portion of the valveclosed for low venting rates.

FIG. 5 is a section through an alternate embodiment of the invention.

release valve 36.

According to a feature of the present invention, an additional fitting37 is provided on the cannister and serves as a base for the valveassembly 38 which has a fitting 39 at the upper end or at the basethereof. A hose 41 fromthis fitting is connected to a vacuum system orpump 42 of the hospital or clinic employing the equipment, for removalof vented gases from the valve assembly 38 and from the operating roomto discharge outside the building at 43, for example. Of course, it willbe recognized that the length of the hose 41 or the other appropriatevacuum line which it may represent, would be much longer in practicethan is-represented in the drawing, where the length is reduced toconserve space. I

Referring particularly to FIGS. 2, 3 and 4, the fitting 37 of FIG. 1serves as a mounting base for a valve body 46, the outer surface '47 ofthe fitting 37 being generally cylindrical, although it may have aslight taper to facilitate molding in plastic and assembly of the parts.The valve body 46 has a generally cylindrical innersurface 48 receivedon the surface 47, and this surface also may have a slight taper tofacilitate molding and assembly of the parts. As shown better in FIGS. 3and 4, the upper margin of the fitting 37 may have a plurality of slots49 therein. Similarily, the lower margin of the skirt portion 51 of .thevalve body, and which has the inner surface 48 perceived on the fitting37, may have a plurality of circularly spaced slots 52 therein. As shownin FIGS. 2 and 3, theslots 52 are in registry with the slots 49. In thiscondition of the parts, gases in the system may escape through fitting37 and may pass upwardly through the annular space 53 and slots 49 and52 into the chamber 54 provided by a cover 56 which is received in theflanged portion 57 of the valve body. A suitable bead may be provided at58 on the flange and at 59 on the cover to permit a snap-inconstruction.

The valve body has a central passageway 61 having an aperture 62 at thelower end thereof and an aperture 63 at the upper end thereof. Theaperture 63 may be partially closed by a tapered pin 64 having a knob 66at the upper end thereof, and having a vertically extending slot 67extending upwardly therein from the lower end of the pin. The pin 64 canbe pushed further down into the aperture 63 to completely close theupper opening of the passageway 61, or it can be completely removed fromthe opening, and will be retained by the flexible link 68 to preventinadvertent loss.

A ball 69 is provided in the passageway, and is free to move from theposition shown where it closes the aperture 62 at the lower end, to aposition against the lower end of the pin 64 when it is in the upperaperture, or the ball can close the upper aperture in the event the pinis removed therefrom, and gas flow upwardly through the passageway movesthe ball against the upper end thereof.

In the use of the apparatus thus far described, according to the methodof the present invention, if it is desired to operate the absorbersystem completely closed, the plug pin 64 will be pushed down into theaperture 63 to the extent such that the slot 67 is completely closed orcompletely below the upper margin 72 of the valve body. Likewise, thevalve body will be turned with respect to the fitting 37 in thedirection of arrow 73 or 74 to such an extent that, as shown in FIG. 4,there is no registry between the slots thereof and those in the fitting.With this arrangement, there is no possibility of gas from the chamber14 being vented through any portion of the assembly 38.

If it is desired to use the apparatus at low venting rates, the cover 56can be removed and the pin 64 pulled slightly upward in the aperture 63.Operation would then continue with an appropriate adjustment of the pin64 to accommodate the volume of gas supplied from the machine 11 throughthe hose 29, without undesired rise of pressure indicated by gauge 34.The amount of exposure of the slot 67 will determine the amount of gasvented. In this condition, the ball 69 can move upwardly in thepassageway to whatever extent the volume of venting gas through thepassageway 61 will lift it. However, in the event the anesthetistsqueezes the re-breathing bag 27, for example, to aid the patient inbreathing, the ball will close against the seat at the lower end of theupper aperture, and prevent venting under such circumstances. Thus thevalve remains compatible with conventional techniques.

In the event the amount of gases to be vented requires complete removalof the pin 64, it will remain hanging beside the valve body by means ofthe strap 68, which may be simply a molded plastic strap adhered to theknob 66 and to some part of the assembly such as the valve body or coverfor example. If additional venting is needed to avoid seating of theball 69, on the lower edge of the upper aperture, 63, the valve body 46can be turned to permit some registry of the openings 49 and 52. In thisway, in addition to the gas vented through the aperture 62, passageway61 and aperture 63, additional gases from the system may be ventedthrough the openings in the base fitting 37 and the valve body skirt.With the cover removed, these gases will simply dissipate into theoperating room atmosphere. As the volume and duration of such ventingincrease, it can have adverse effects on the personnel therein. To avoidthis, the 56 may simply be snapped into place, and the vented gasestherefrom exhausted by the vacuum system 41-42 of FIG. 1, for example.

In order to avoid excessive evacuation due to the connection of thevacuum system to the cover 56, additional vents 76 may be provided inthe flange 57, for example, to permit air from the atmosphere to bedrawn up into the cover and out the fitting 39. Also, of course, it ispossible to provide a valve in the vacuum line as at 77, for example, orto reduce the area of registry of openings 49 and 52.

The sizing of the various components may be such that, for example,various adjustments of the pin 64 will suffice, while the openings 49-52remain closed, for flow rates up to 4 litres. Removal of pin 64 andincreases of opening of valve body vents may be employed for increasingflow rates above 4 litres per minute.

Referring now to FIG. 5, there is shown a recess 81 in the top of thecanister and which projects partially into the chamber 14. Projectingupwardly from the bottom of this recess is a cylinder 82 which receivesthe valve ball 83 in the same manner as the passageway 61 received thevalve ball 69. An aperture 84 is provided in the wall of the internalpassageway 86 in cylinder 82. The ball can thus move between a positioncovering the lower aperture 87 and a position covering the upperaperture 88 in the passageway 86.

The cylinder 82 has a screw thread 89 molded on the exterior surfacethereof which receives the single turn of thread 91 molded on theinternal cylindrical wall 92 of the cover member 93. This wall 92 has anaperture therein at 94. A tab 96 is provided on the upper end tofacilitate turning the cover 93 about the axis 97 to thread it down intothe recess in the direction of arrow 98 or upwardly in the direction ofarrow 99. A fitting 101 is provided at the upper end of the cover forthe same purpose as described above with reference to the previouslydescribed embodiment.

In the use of the embodiment of FIG. 5, the recessed construction servesto conserve space during shipment. In this event, the cover 93 is turnedcompletely down into the recess. For use of the device with the covercompletely turned down, the underside thereof at 102 seats on the upperend gasket 103 of the cylinder 82 for a completely closed system. Topermit venting of gas from the chamber 14, the thumb grip 96 is grippedbetween the thumb and forefinger, and the cover is turnedcounterclockwise (looking down upon the unit) which starts it movingupwardly in the direction of arrow 99. The initial upward movementthereof, of course, opens the aperture 88 and permits venting of gasthrough the aperture 87 up the passageway 86 through aperture 88 and outthrough aperture 94 to the space 104 under the cover, from which it canmove out in the direction of arrow 106 into the atmosphere of theoperating room. As the cover is further raised by further rotationthereof on the member 82, the size of the passageway for venting ofgases increases. At some point, the flow upward through the passageway86 may be such as to seat the ball 83 on the lower edge of the upperaperture 88, whereupon further venting will take place through theaperture 84 in the wall 82 and up in the space 107 between cylinder 82and cylinder 108 and out the vent 94. Also, as with the previouslydescribed embodiment, a slot can be provided in the lower margin of thecylinder 108 as indicated at 109 to permit registry thereof with theopening 84 and permit direct venting through the registry openings tothe areas under the cover. The evaculation of the area under the covercan be accomplished by connecting a vacuum system hose to the fitting101 as described above with reference to the other embodiment of theinvention.

In the construction of both embodiments of the present invention, allparts can be made of molded plastic. If desired, the ball can be a steelball of the type conventionally used in ball bearings. The gasketemployed in the embodiment of FIG. 5 can be of a soft plastic or rubberor other suitable material. While materials other than plastics may beemployed, it seems that plastics will be most suitable, and of course,lend themselves to transparent construction which can be desirableparticulary from the standpoint of general appearance, and the abilityto thereby see the position of the ball in the passageway in the pop-offvalve.

Although the top of the cannister is a convenient site for the valveassemblies of the present invention, their construction adapts them toconvenient mounting at other locations on a circle absorber system, ifdesired.

The invention claimed is:

l. A valve assembly comprising:

a mount having a first generally cylindrical wall surface with firstopening means therein,

a body having a second generally cylindrical wall surface thereonreceived around said first wall surface, said second wall surface havingsecond opening means therein, said body being fitted on said mount andmanually rotatable on colinear axes of said generally cylindricalsurfaces for varying degrees of registry between the said first andsecond opening means, the said first opening means of said mountcommunicating with a first chamber to be vented,

said body having cover receiver means thereon,

said generally cylindrical wall surfaces being slightly tapered anddisposed in facing rotatably sliding relationships whereby said body issupported on said mount,

an internal elongated passageway in said body, said passageway having anaperture in each end;

a valve movable longitudinally in said passageway and capable ofpositioning at said end apertures alternately, and capable of closingone of said apertures.

2. The assembly of claim 1 wherein said valve is a ball and said body istransparent for visibility of said ball therein.

3. The assembly of claim 1 wherein:

said body has a cap thereon with a stem projecting through one of saidapertures into said passageway.

4. A valve assembly comprising:

a mount having a first generally cylindrical wall surface with firstopening means therein,

a body having a second generally cylindrical wall surface thereonreceived around said first wall sur face, said second wall surfacehaving second opening means therein, said body being fitted on saidmount and manually rotatable on colinear axes of said generallycylindrical surfaces for varying degrees of registry between the saidfirst and second opening means, the said first opening means of saidmount communicating with a first chamber to be vented,

said body having cover receiver means thereon,

said generally cylindrical wall surfaces being slightly tapered anddisposed in facing rotatably sliding relationship whereby said body issupported on said mount,

a cover received on said cover receiver and providing a second chamber,said second opening means in said body communicating with said secondchamber and cooperating with said first opening means in said mount tovent gases from said first chamber to said second chamber.

5. The assembly of claim 4 wherein:

said cover receiver means are positioned to accommodate simultaneousturning of said body with said cover to vary the degree of registry ofsaid second opening means with said first opening means.

6. The assembly of claim 4 wherein:

said cover has an outlet thereon for evacuation of said vented gasesfrom said second chamber.

7. The assembly of claim 6 wherein:

said cover receiver means has inlet vent means therein located such thatsaid second opening means in said body are adjacent a flow path fromsaid inlet vent means to said outlet.

1. A valve assembly comprising: a mount having a first generallycylindrical wall surface with first opening means therein, a body havinga second generally cylindrical wall surface thereon received around saidfirst wall surface, said second wall surface having seconD opening meanstherein, said body being fitted on said mount and manually rotatable oncolinear axes of said generally cylindrical surfaces for varying degreesof registry between the said first and second opening means, the saidfirst opening means of said mount communicating with a first chamber tobe vented, said body having cover receiver means thereon, said generallycylindrical wall surfaces being slightly tapered and disposed in facingrotatably sliding relationships whereby said body is supported on saidmount, an internal elongated passageway in said body, said passagewayhaving an aperture in each end; a valve movable longitudinally in saidpassageway and capable of positioning at said end apertures alternately,and capable of closing one of said apertures.
 2. The assembly of claim 1wherein said valve is a ball and said body is transparent for visibilityof said ball therein.
 3. The assembly of claim 1 wherein: said body hasa cap thereon with a stem projecting through one of said apertures intosaid passageway.
 4. A valve assembly comprising: a mount having a firstgenerally cylindrical wall surface with first opening means therein, abody having a second generally cylindrical wall surface thereon receivedaround said first wall surface, said second wall surface having secondopening means therein, said body being fitted on said mount and manuallyrotatable on colinear axes of said generally cylindrical surfaces forvarying degrees of registry between the said first and second openingmeans, the said first opening means of said mount communicating with afirst chamber to be vented, said body having cover receiver meansthereon, said generally cylindrical wall surfaces being slightly taperedand disposed in facing rotatably sliding relationship whereby said bodyis supported on said mount, a cover received on said cover receiver andproviding a second chamber, said second opening means in said bodycommunicating with said second chamber and cooperating with said firstopening means in said mount to vent gases from said first chamber tosaid second chamber.
 5. The assembly of claim 4 wherein: said coverreceiver means are positioned to accommodate simultaneous turning ofsaid body with said cover to vary the degree of registry of said secondopening means with said first opening means.
 6. The assembly of claim 4wherein: said cover has an outlet thereon for evacuation of said ventedgases from said second chamber.
 7. The assembly of claim 6 wherein: saidcover receiver means has inlet vent means therein located such that saidsecond opening means in said body are adjacent a flow path from saidinlet vent means to said outlet.